Zero clearance fireplaces of the type with which this invention is concerned have been known for some time. These fireplaces generally provide a firebox having a combustion chamber within an outer shell, about which air may be circulated to and from the room. There is no required clearance between the outer shell and the studwork or other structures within which it is retained. The combustion chamber within the firebox is physically separated from the convection air used to heat the room interior. In constructions heretofore in use, including a fireplace construction, exemplified by U.S. Pat. No. 4,574,773, issued Mar. 11, 1986 to Moughamiam, the firebox opening has been closed by a guillotine-type glass panel or door that slides in lateral slides or channels. Similar constructions have been used and disclosed in other patents including U.S. Pat. No. 4,169,459, issued Oct. 2, 1979 to Shaw; U.S. Pat. No. 1,213,173, issued Jan. 20, 1917 to Evans; U.S. Pat. No. 244,397, issued Jul. 19, 1881 to Matthews; and U.S. Pat. No. 579,987, issued Apr. 6, 1897 to Jordan. These and other prior art references including U.S. Pat. No. 1,726,874, issued Sept. 3, 1929 to Mumford; U.S. Pat. No. 2,803,241, issued Aug. 20, 1957 to Chapla; U.S. Pat. No. 4,287,871, issued Sept. 8, 1981 to Schumann; U.S. Pat. No. 2,775,239, issued Dec. 25, 1956 to Bucci; U.S. Pat. No. 4,294,224, issued Oct. 13, 1981 to Luther; U.S. Pat. No. 4,086,906, issued May 2, 1978 to Reichgut; U.S. Pat. No. 4,183,348, issued Jan. 15, 1980 to Smith; U.S. Pat. No. 4,270,514, issued Jun. 2, 1981 to Berry; U.S. Pat. No. 4,059,091, issued Nov. 22, 1977 to Hobb; U.S. Pat. No. 579,987, issued Apr. 6, 1897 to Jordan; U.S. Pat. No. 244,397, issued Jul. 19, 1881 to Matthews; U.S. Pat. No. 4,271,815, issued Jun. 9, 1981 to Johnson; U.S. Pat. No. 4,572,156, issued Feb. 25, 1986 to Lentz; and U.S. Pat. No. 4,576,141, issued Mar. 18, 1986 to Lillard, generally disclose the use of guillotine-type glass door closures in combination with screen closures for fireplace constructions. Nonetheless, these prior art fireplaces appear to have inherent air leaks from the combustion chamber because the glass door seal against the combustion chamber is not particularly tight. In these prior art constructions, spaces between the glass door and the periphery about the combustion chamber opening permitted movement of the air between the combustion chamber and the room. Such air movement makes these fireplaces less efficient.
In addition, the arrangements disclosed in the prior art do not provide suitable means for maintaining a clean glass door. Means are not provided for minimizing deposit of soot on the inner surface of the glass door or for facilitating the cleaning of this glass door on both sides. In addition, those prior art devices in which glass doors were closed in a guillotine-type action, involved hand-operated closing mechanisms. Additionally, these systems had balancing systems, such that the glass door would remain closed if unattended even if not positively locked in a down position. In those systems, no means were provided for easily opening the glass door from within the combustion chamber. As a result, there is an inherent possibility that the glass doors disclosed in prior art guillotine systems might trap a youngster inside the combustion chamber.
These prior art systems, moreover, do not lend themselves for installation in a variety of designs and styles.